A fluid machine has first (21A) and second walls (21B), a gaspath defined between the first wall (21A) and the second wall (21B); a rotor having blades rotatable about the central axis (11) and a stator (31) having a row of vanes (33) having airfoils (35) including leading edges (35A), trailing edges (35B), pressure sides (35C) and suction sides (35D) opposed the pressure sides (35C), and depressions (40) defined in the first wall (21A), the depressions (40) extending from a baseline surface (BS) of the first wall (21A) away from the second wall (21B), a depression (40) of the depressions (40) located circumferentially between a pressure side (35C) of the pressure sides (35C) and a suction side (35D) of the suction sides (35D), the depression (40) axially overlapping the airfoils (35) and extending in a downstream direction from an upstream end to a downstream end, the downstream end located closer to a trailing edge (35B) of the trailing edges (35B) than to a leading edge (35A) of the leading edges (35A).